1. Field of Invention
Various exemplary embodiments of the present invention relate generally to an electronic device, and more particularly, to a semiconductor memory device and a method of operating the same.
2. Description of Related Art
Non-volatile memory devices operate at relatively low write and read speeds, but they can retain the stored data regardless of power on/off conditions. Volatile memory devices are considered to operate at high write and read speeds, but they are unable to retain the stored data when the power is off. Examples of non-volatile memory include Read Only Memory (ROM), Mask ROM (MROM), Programmable ROM (PROM), Erasable Programmable ROM (EPROM), Electrically Erasable and Programmable ROM (EEPROM), flash memory, Phase-change Random Access Memory (PRAM), Magnetic RAM (MRAM), Resistive RAM (RRAM) and Ferroelectric RAM (FRAM). Flash memories are categorized into a NOR type or a NAND type.
Flash memories enjoy the advantages of both RAM and ROM. For example, flash memories may be freely programmed and erased similar to RAM. Similar to ROM, flash memories may retain the stored data even when they are not powered. Flash memories have been widely used as the storage media of portable electronic devices such as mobile phones, digital cameras, personal digital assistants (PDAs), and MP3 players.
In line with the development of storage solution products including flash memories to store data, such as solid state drive/disk (SSD) and embedded multi-media card (eMMC), the data input/output speed of a semiconductor memory device has become an increasingly important issue.